Background: Raman spectroscopy is a well-known tool used in criminology, molecular biology, and histology. It is also applied to diagnose bone mineral disorders by taking advantage of the similarity of the structure of keratin and bone collagen. Raman spectroscopy can also be used in dermatology and diabetology. The purpose of the present review is to critically evaluate the available research about the use of Raman spectroscopy in the mentioned areas of medicine. Methodology: PubMed was searched for peer-reviewed articles on the subject of use of Raman spectroscopy in bone mineral disorders, dermatology, and diabetes mellitus. Results: Nail keratin and bone collagen are related structural proteins that require disulfide bond for structural stability. Therefore, Raman spectroscopy of keratin may have potential as a diagnostic tool for screening bone quality and distinguishing patients at risk of fracture for reasons different from low bone mineral density (BMD) in the adult women population. Raman spectroscopy can also investigate the changes in keratin’s structure in nails affected by onychomycosis and distinguish between healthy and onychomycosis nail samples. It could also reduce the need for nail biopsy by distinguishing between dermatophytic and non-dermatophytic agents of onychomycosis. Additionally, Raman spectroscopy could expedite the diagnostic process in psoriasis (by assessing the secondary structure of keratin) and in diabetes mellitus (by examining the protein glycation level). Conclusions: In adult populations, Raman spectroscopy is a promising and safe method for assessing the structure of fingernails. However, data are scarce in the pediatric population; therefore, more studies are required in children.

Introduction and objective: This pilot study aimed to evaluate the feasibility of attenuated total reflectance – Fourier transform infrared spectroscopy (ATR FTIR) as a rapid, non-invasive method for detecting biochemical alterations in the fingernails of paediatric patients with inflammatory bowel disease (IBD). Materials and methods: ATR FTIR spectra were acquired from fingernail clippings obtained from 10 children diagnosed with IBD and from 10 age-matched healthy controls. Spectral analysis focused on characteristic vibrational bands associated with keratin structure, including N–H stretching vibrations, asymmetric CH₂ and CH₃ stretching modes, and symmetric CH₃ vibrations. Results: Comparative spectral analysis revealed subtle but consistent differences between the IBD and control groups. Shifts in bands related to keratinassociated amino acids were observed, particularly in the regions corresponding to N–H and C–H stretching vibrations. The most pronounced difference was detected at 1,745 cm⁻¹, attributed to C = O stretching vibrations, suggesting alterations related to oxidative processes in the fingernails of children with IBD. Conclusions: ATR FTIR spectroscopy demonstrated potential for identifying disease-related biochemical changes in the fingernails of paediatric patients with IBD. The observed spectral differences indicate keratin derangements associated with oxidative stress and visible nail alterations. These preliminary findings justify further investigation of ATR FTIR fingernail analysis in larger cohorts and its potential role in monitoring disease-related biochemical changes and dietary interventions, including antioxidant strategies.